1. Field
The present invention relates generally to communication systems, and particularly to Internet Engineering Task Force (IETF) Internet Protocol (IP) mobility and Third Generation Partnership Project (3GPP) Evolved Packet Core communication systems using Proxy Mobile IPv6 (PMIPv6) based protocols. The present invention also relates to Worldwide Interoperability for Microwave Access (WiMAX) networks which use PMIPv6 as a network-based mobility protocol.
2. Description of the Related Art
PMIPv6 is a network-based mobility management protocol which enables IP mobility for a mobile node without requiring the mobile node's participation in any mobility-related signaling. According to the PMIPv6 protocol, the core functional entities in the infrastructure of the PMIPv6 protocol are the Local Mobility Anchor (LMA) and the Mobile Access Gateway (MAG). When a mobile node enters a PMIPV6 domain, the MAG, after identifying the mobile node and acquiring its identity, determines if the mobile node is authorized for the network-based mobility management service. If the MAG determines that the mobile node is authorized for network-based mobility service, the MAG will determine an address of an LMA, and send a signaling request message to the LMA to establish an IP session. If the selected LMA is capable of serving the mobile node, the LMA will send an acknowledgment message to the MAG, and a bi-directional tunnel is established between the MAG and the LMA.
However, there are situations where the selected LMA is not capable of serving the mobile node. For example, the LMA may not be able to allocate any home network prefixes for the mobile node due to insufficient resources. In these situations, the LMA must reject the request message of the MAG, and the MAG must locate another LMA.
In these situations, there is no mechanism where the selected LMA may redirect the request message to an alterative LMA which may be capable of serving the mobile node. There is no known mechanism, or defined support in the PMIPv6 protocol, for the redirection of an IP session establishment to an alternative LMA and for load-balancing between a set of LMAs.